Weird graphics problem

[Zeating]

Recently most games on my computer have just stopped working, or are acting very strange. For example, when i go into halo 1 sometimes i can't see any models, and some maps dont work and it crashes. Also if i try to play Call of Duty 4 when it loads it says "DIRECT X FAILURE" I've tried reinstalling and getting the latest versions of DirectX but nothing is working.. I've also tried reinstalling + updating my graphics drivers.
I have a HIS ATI Radeon 4850

Edit: Also, i deleted Directx 9 and in Dxdiag it says Direct X version unknown, now when i try to install it again it says "An internal error has occurred please refer to DXError.log and DirectX.log in your windows folder to determine problem"

 

[Tmagic650]

Your listed specs are very minimal. Did you build or buy this computer? What is the model and make of the computer? Are you running XP Service Pack 3?

 

[Zeating]

I dont think my specs are necessary because the game was working just fine a few days ago..

Im running XP SP3, with a dual core 2.5ghz procsser, 2gigs of ram, and a gigabyte mobo.

 

[Zeating]

I just got into cod 4 multiplayer after waiting 20 mins of loading, and the screen is messed up. All the models and stuff are green/blueish and most of the textures are invisible.. this is weird

 

[Tmagic650]

System specs are always helpful on this site. We are not there with you. We cannot see your computer or its screen. System specs and the OS can give us clues to the trouble, many times, more than the users words can provide. Your power supply might be failing. Try another power supply, then go after another video card